Transcript 2. Where are electrons found in an atom?

All matter is made up of
ATOMS.
Identify each labeled structure in the atom. Describe the
charge for each particle.
A
B
A – Electron
Electrons have a
negative charge.
B – Neutron
Neutrons have no
charge (neutral).
C - Proton
C
Protons have a
positive charge.
1. Where are protons and neutrons found
in an atom?
In the nucleus of an atom.
2. Where are electrons found in an atom?
Outside the nucleus of an atom.
Which of the following is not an
element?
1. oxygen 2. sodium chloride
3. hydrogen 4. nitrogen
A positively charged particle is a
PROTON.
Which subatomic particle would be
found outside the nucleus of an
atom?
ELECTRON
A chemical formula like CO2
represents
1. an element
2. an atom
2. an electron 4. a compound
A substance made up of two or more
elements that have been
chemically combined is a
COMPOUND.
A substance made up of two or more
elements that have been physcially
combined is a
MIXTURE.
A substance that cannot be
changed into simpler substances
by a chemical change is called a
(an)
1. element.
2. liquid.
3. solid.
4. mixture.
In sweetened tea, the sugar is
called the
1. solute.
2. solvent.
3. colloid.
4. solution.
Which of the following would help
sugar dissolve faster in water?
1. stirring the water
2. decreasing the solubility of sugar
3. using larger particles of sugar
4. decreasing the water temperature
Describe the difference between
a soluble and insoluble
substance.
A soluble substance easily dissolves in a solvent.
An insoluble substance DOES NOT dissolve in a solvent.
Sand and iron particles that are similar in
size and color are mixed together in a
beaker. What would be the best method
of separating the particles?
1. Use tweezers to separate them.
2. Add water to the mixture.
3. Use a magnet to separate them.
4. Pour the mixture into a filter.
The substances in a mixture can be
separated by physical means because
1. no chemical change occurs when the
substances are combined.
2. the physical and chemical properties of
the substances change.
3. none of the properties of the
substances change.
4. the chemical, but not the physical,
properties of the substances change.
•Mass number
80
•# of protons
35
•# of electrons
35
•# neutrons
45
•Mass number
112
•# of protons
48
•# of electrons
48
•# neutrons
64
•Mass number
•# of protons
•# of electrons
•# neutrons
All samples of an element are
composed of atoms with the same
1. atomic mass
2. atomic number
3. number of protons and neutrons
4. number of neutrons
Elements at the left of the
periodic table are known as
METALS
Elements at the right of the
periodic table are known as
NONMETALS
The elements oxygen, sulfur, selenium and tellurium are
all found in the same group (16) on the table. What do
we know about the elements in that family?
They have the same (BUT NOT IDENTICAL)
properties.
1. In what family is neon found? Family 18
2. What do we call those elements in that group?
Noble gases
Which element is a metalloid?
1. S (Sulfur)
2. Si (Silicon)
3. Ba (Barium) 4. Br (Bromine)
Explain what occurs to the atomic number
when moving from left to right on the
periodic table.
Atomic number increases.
Which three elements have the most
similar chemical properties?
1. Ar, Kr, Br
2. K, Rb, Cs
3. B, C, N
4. O, N, Si
Which element is a noble gas?
1.hydrogen
2.oxygen
3.neon
4.nitrogen
Identify the solid, liquid and gas! Support your answer.
Gas
- Atoms are
very loosely
packed
Solid
Liquid
- Atoms are
tightly packed
- Atoms are
loosely
packed
Identify the phase change described.
1. Solid to liquid: melting
2. Gas to liquid: condensation
3. Liquid to solid: freezing
4. Solid to gas: sublimation
5. Liquid to gas: vaporization
For each phase change describe
whether energy is RELEASED or
ABSORBED.
1. Melting: ABSORBED
2. Freezing: RELEASED
3. Vaporization: ABSORBED
4. Sublimation: ABSORBED
5. Condensation: RELEASED
The particles of a substance are
closest together in
1. a solid
2. a liquid
3. a gas
4. plasma
The particles of a substance move
most readily in
1. a solid
2. a liquid
3. a gas
The particles of a substance that does
not have a definite volume or
shape is
1. a solid
2. a liquid
3. a gas
Attractive forces are very strong
between particles in
1. a solid
2. a liquid
3. a gas
4. plasma
When a liquid becomes a solid,
energy
1. does not change
2. is released
3. is absorbed
4. is first absorbed, then released
_______ is the process in which
liquid changes to gas.
1. Sublimation
2. Condensation
3. Evaporation
4. Combustion
The change of a liquid to a solid is
called
1. freezing
2. melting
3. sublimation
4. vaporization
When substances go directly from the
solid phase to the gas phase, the
phase change is called
1. sublimation
2. condensation
3. evaporation
4. vaporization
For the following pictures,
identify whether a physical or
chemical change is occurring.
Physical
Chemical
Chemical
Physical
Physical
Chemical
Chemical